Blood glucose and plasma insulin responses to various carbohydrates in type 2 (non-insulin-dependent) diabetes

Effect of honey on glucose and insulin concentrations in obese girls

BACKGROUND

Childhood obesity represents a major health problem of our century. The benefits of natural products, such as honey, in the management of obesity have gained renewed interest. In this study, we investigated the effect of honey on glucose and insulin concentrations in obese prepubertal girls.

MATERIALS AND METHODS

Thirty healthy obese girls aged 10.55 (±SEM:0.34) years with a mean body mass index (BMI) above the 97th centile for age (28.58 ± 1.40 kg/m² , BMI z-score 2.96) underwent a standard oral glucose tolerance test (OGTT) followed by an oral honey tolerance test (OHTT) 2 weeks later. Both solutions contained 75 g of glucose. Subsequently, subjects were randomized to receive either 15 g of honey or 15 g of marmalade daily, while both groups complied with dietetic instructions. Six months later all subjects were re-evaluated with an OGTT and an OHTT.

RESULTS

At the end of the study, all subjects demonstrated a significant reduction in BMI (27.57 ± 1.40, z-score: 2.54 vs 28.58 ± 1.40 kg/m² , z-score: 2.96, P < 0.001), however, there were no significant differences in BMI and all parameters tested between the group that received honey and the control group. The areas under the concentration-time curve for glucose and insulin for the entire population were significantly lower following ingestion of honey than glucose solution (P < 0.001) both at the beginning and at the end of study.

CONCLUSIONS

These findings indicate that honey does not have an effect on stimulated plasma glucose and serum insulin concentrations compared with the standard glucose solution in obese prepubertal girls.

Honey and Diabetes: The Importance of Natural Simple Sugars in Diet for Preventing and Treating Different Type of Diabetes

Diabetes is a metabolic disorder with multifactorial and heterogeneous etiologies. Two types of diabetes are common among humans: type 1 diabetes that occurs when the immune system attacks and destroys insulin and type 2 diabetes, the most common form, that may be caused by several factors, the most important being lifestyle, but also may be determined by different genes. Honey was used in folk medicine for a long time, but the health benefits were explained in the last decades, when the scientific world was concerned in testing and thus explaining the benefits of honey. Different studies demonstrate the hypoglycemic effect of honey, but the mechanism of this effect remains unclear. This review presents the experimental studies completed in the recent years, which support honey as a novel antidiabetic agent that might be of potential significance for the management of diabetes and its complications and also highlights the potential impacts and future perspectives on the use of honey as an antidiabetic agent.

Honey and cardiovascular risk factors, in normal individuals and in patients with diabetes mellitus or dyslipidemia

Diabetes mellitus, hypercholesteremia, hypertension (HTN), and obesity are well-known risk factors for cardiovascular diseases (CVD). Various medications are currently in use for management of these comorbidities. Undesirable side effects are unavoidable and the ultimate and ideal goal is hardly achieved. Honey and other bee products are widely used in traditional medicine for management of many diseases. Others and the authors have found potent biological activities of these products. Honey is now reintroduced in modern medicine as part of wound and burn management. Honey has antioxidant, anti-inflammatory, and antimicrobial activities. More studies are exploring other aspects of honey activity such as its effect on blood sugar, body weight, lipid profile, C-reactive protein, nitric oxide, proinflammatory prostaglandins, and homocysteine. Growing evidence and scientific data support the use of honey in patients with diabetes, HTN, dyslipidemia, obesity, and CVD. This review discusses clinical and preclinical studies on potential influence of honey on diabetes mellitus and cardiovascular risk factors, and emphasizes the importance of conducting more clinical and controlled studies.

Metabolic effects of honey in type 1 diabetes mellitus: a randomized crossover pilot study

The aim of this study was to evaluate the metabolic effects of 12-week honey consumption on patients suffering from type 1 diabetes mellitus (DM). This was a randomized crossover clinical trial done in the National Institute for Diabetes and Endocrinology, Cairo, Egypt. Twenty patients of both sexes aged 4-18 years with type 1 DM and HbA1C<10% participated in the study. They were randomized into two equal groups (intervention to control and control to intervention). The dietary intervention was 12-week honey consumption in a dose of 0.5 mL/kg body weight per day. The main outcome measures were serum glucose, lipids, and C-peptide, and anthropometric measurements. None of participants were lost in follow-up. The intervention resulted in significant decreases in subscapular skin fold thickness (SSFT; P=.002), fasting serum glucose (FSG; P=.001), total cholesterol (P=.0001), serum triglycerides (TG; P=.0001), and low-density lipoprotein (P=.0009), and significant increases in fasting C-peptide (FCP; P=.0004) and 2-h postprandial C-peptide (PCP; P=.002). As possible long-term effects of honey after its withdrawal, statistically significant reductions in midarm circumference (P=.000), triceps skin fold thickness (P=.006), SSFT (P=.003), FSG (P=.005), 2-h postprandial serum glucose (P=.000), TG (P=.003), and HbA1C (P=.043), and significant increases in FCP (P=.002) and PCP (P=.003) were observed. This small clinical trial suggests that long-term consumption of honey might have positive effects on the metabolic derangements of type 1 DM.

Fructose might contribute to the hypoglycemic effect of honey

Honey is a natural substance with many medicinal properties, including antibacterial, hepatoprotective, hypoglycemic, antioxidant and antihypertensive effects. It reduces hyperglycemia in diabetic rats and humans. However, the mechanism(s) of its hypoglycemic effect remain(s) unknown. Honey comprises many constituents, making it difficult to ascertain which component(s) contribute(s) to its hypoglycemic effect. Nevertheless, available evidence indicates that honey consists of predominantly fructose and glucose. The objective of this review is to summarize findings which indicate that fructose exerts a hypoglycemic effect. The data show that glucose and fructose exert a synergistic effect in the gastrointestinal tract and pancreas. This synergistic effect might enhance intestinal fructose absorption and/or stimulate insulin secretion. The results indicate that fructose enhances hepatic glucose uptake and glycogen synthesis and storage via activation of hepatic glucokinase and glycogen synthase, respectively. The data also demonstrate the beneficial effects of fructose on glycemic control, glucose- and appetite-regulating hormones, body weight, food intake, oxidation of carbohydrate and energy expenditure. In view of the similarities of these effects of fructose with those of honey, the evidence may support the role of fructose in honey in mediating the hypoglycemic effect of honey.

The glycemic and peak incremental indices of honey, sucrose and glucose in patients with type 1 diabetes mellitus: effects on C-peptide level-a pilot study

Our study was a case-control cross-sectional study that was conducted on 20 children and adolescents suffering from type 1 diabetes mellitus and ten healthy non-diabetic children and adolescents serving as controls. The mean age of patients was 10.95 years. Oral sugar tolerance tests using glucose, sucrose and honey and measurement of fasting and postprandial serum C-peptide levels were done for all subjects in three separate sittings. The glycemic index (GI) and the peak incremental index (PII) were then calculated for each subject. Honey, compared to sucrose, had lower GI and PII in both patients (P < 0.001) and control (P < 0.05) groups. In the patients group, the increase in the level of C-peptide after using honey was not significant when compared with using either glucose or sucrose. However, in the control group, honey produced a significant higher C-peptide level, when compared with either glucose or sucrose. In conclusion, honey, because of its lower GI and PII when compared with sucrose, may be used as a sugar substitute in patients with type 1 diabetes mellitus.

Extended prandial glycemic profiles of foods as assessed using continuous glucose monitoring enhance the power of the 120-minute glycemic index

BACKGROUND

The glycemic index (GI) is routinely measured 120 minutes after food intake (GI120). The purpose of this prospective open label study was to assess (1) the dynamics of glycemia over the 210 minutes following food consumption and (2) the evolution of GIs based on 120-, 150-, 180-, and 210-minute glycemic profiles.

METHOD

Twenty healthy subjects (mean +/- SE; 21.9 +/- 1.39 years of age; body mass index 23.6 +/- 0.63 kg/m(2); 7 men and 13 women) completed the study. Each subject consumed 10 different foods with known GI120 on three separate occasions at four different times of day according to a defined meal plan over a 9-day period; 32 meals were evaluated. The GIs for intervals of 120, 150, 180 and 210 minutes after food consumption were determined using a continuous glucose monitoring system (CGMS) to measure glycemia. The Wilcoxon signed-rank test was applied to compare the GIs.

RESULTS

Glycemia returned to baseline within 120 minutes for honey and tomato soup; within 210 minutes for white bread, choco-rice cookies, fish and potatoes, wafers, and meat ravioli with cheese; and later for dark chocolate, apricot dumplings, and choco-wheat cookies. The extended GIs were higher than the respective GI120s in eight of the foods.

CONCLUSIONS

The 120-minute glycemic index fails to fully account for changes in glycemia after ingestion of a mixed meal because glycemia remains above baseline for a longer period. The CGMS is a convenient method to determine the glucose response/GIs over intervals extended up to 210 minutes, which is adequate time for the absorption of most foods.

Evaluation of the new software program DegifXL4 in the determination of the glycaemic indices of foodstuffs

AIMS

There is no standardized protocol for measuring glycemic index (GI) that takes time-of-day effects into account. The software DegifXL2 and Medtronic-Minimed's CGMS and Solutions, makes the GI calculation at breakfast and dinner time possible. The aim of this study was to assess the enhanced data processing software (DegifXL4) enabling the GI calculation at breakfast, lunch, afternoon snack and dinner times.

METHODS

The glucose levels of 20 healthy volunteers were monitored after they consumed either 50 g of glucose or one of ten alternative foodstuffs either for breakfast and dinner or for lunch or snack. Within the 9-day test period, 10 such meals were monitored in 3 replicates for each volunteer. Specifically, CGMS was used to monitor plasma glucose levels at 5-minute intervals for a period of 120 min following the foodstuff ingestion.

RESULTS

Using the enhanced spreadsheed DegifXL 4, a total of 640 profiles were obtained and 491 (77 %) accomplished the criteria for further processing. The percentage of successful tests in each foodstuff varied from 57 to 87 %.

CONCLUSIONS

The use of the new software DegifXL4 offers accurate GI estimates for foodstuffs eaten for breakfast, lunch, snacks and dinners in three replicates. In combination with the CGMS Solutions Software is DegifXL4 an enhanced efficient and comfortable way to routinely measure GI values.

Automated computation of glycemic index for foodstuffs using continuous glucose monitoring

BACKGROUND

The glycemic index (GI) is a measure of the ability of a food to raise glucose levels after it is eaten. Continuous glucose monitoring (CGM) has been shown to give identical values of GI when compared to traditional methods. However, there has been no standardized protocol for measuring GI that takes into account interindividual variability and chronophysiological glycemic response to food. Our aim was (1) to create and describe software based on a Microsoft Excel 2000 spreadsheet to facilitate rapid, automated, accurate, and standardized processing of data obtained using recent CGM methodology to measure GI and its variability and (2) to assess the benefits of this new approach.

METHOD

Twenty healthy subjects consumed 50 grams of glucose or four alternative foodstuffs (chocolate, apple baby food, rice squares, or yogurt) at breakfast and dinner during 1 week, resulting in 300 CGMS glucose profiles; 92% of meal tests were satisfactory for evaluation. Application and functions of the software DegifXL are described.

RESULTS

Using the new spreadsheet software DegifXL, time required for data processing for the 15 data sets for each subject was reduced from 2000 to 160 minutes relative to previously used manual methods. We characterized the GI for four foodstuffs with three replicate measurements in each of 20 subjects and evaluated between person, between time period, and between replicate GI variabilities.

CONCLUSION

DegifXL, combined with CGM, was an efficient and effective tool for routine measurement of group- and subject-related GI.

Subjects with Impaired Glucose Tolerance Exhibit a High Degree of Tolerance to Honey

The present study compared the relative tolerance to honey and glucose of subjects with impaired glucose tolerance or mild diabetes. Thirty individuals 35-60 years old with a proven parental (mother or father) history of type II diabetes mellitus were subjected simultaneously to an oral glucose tolerance test (GTT) and a honey tolerance test (HTT). Glucose tolerance was found to be impaired in 24 subjects, while six of the subjects were diagnosed as mildly diabetic. All subjects with impaired glucose tolerance exhibited significantly lower plasma glucose concentrations after consumption of honey at all time points of the HTT in comparison to the GTT. The plasma glucose levels in response to honey peaked at 30-60 minutes and showed a rapid decline as compared to that to glucose. Significantly, the high degree of tolerance to honey was recorded in subjects with diabetes as well, indicating a lower glycemic index of honey. Thus, it is evident from the present investigation that honey may prove to be a valuable sugar substitute for subjects with impaired glucose tolerance or mild diabetes.

Glycaemic index, glycaemic load and risk of endometrial cancer: a prospective cohort study

Objective

High-glycaemic-load diets may increase endometrial cancer risk by increasing circulating insulin levels and, as a consequence, circulating oestrogen levels. Given the paucity of epidemiological data regarding the relationship between dietary glycaemic index and glycaemic load and endometrial cancer risk, we sought to examine these associations using data from a prospective cohort study.

Design, setting and subjects

We examined the association between dietary glycaemic load and endometrial cancer risk in a cohort of 49 613 Canadian women aged between 40 and 59 years at baseline who completed self-administered food-frequency questionnaires between 1982 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000.

Results

During a mean of 16.4 years of follow-up, we observed 426 incident cases of endometrial cancer. Hazard ratios for the highest versus the lowest quartile level of overall glycaemic index and glycaemic load were 1.47 (95% confidence interval (CI) = 0.90–2.41; P for trend = 0.14) and 1.36 (95% CI = 1.01–1.84; P for trend = 0.21), respectively. No association was observed between total carbohydrate or total sugar consumption and endometrial cancer risk. Among obese women (body mass index > 30 kg m−2) the hazard ratio for the highest versus the lowest quartile level of glycaemic load was 1.88 (95% CI = 1.08–3.29; P for trend = 0.54) and there was a 55% increased risk for the highest versus the lowest quartile level of glycaemic load among premenopausal women. There was also evidence to support a positive association between glycaemic load and endometrial cancer risk among postmenopausal women who had used hormone replacement therapy.

Conclusions

Our data suggest that diets with high glycaemic index or high glycaemic load may be associated with endometrial cancer risk overall, and particularly among obese women, premenopausal women and postmenopausal women who use hormone replacement therapy.

US Honeys Varying in Glucose and Fructose Content Elicit Similar Glycemic Indexes

The glycemic index of honey may vary, depending upon its floral variety and fructose-to-glucose ratio. We determined the glycemic index of four US honey varieties in 12 healthy adult men and women with a mean (+/-standard error) age of 24.5+/-1.5 years. The glycemic index of 250-mL solution servings of clover, buckwheat, cotton, and tupelo honeys providing 50 g carbohydrate were assessed relative to triplicate feedings of 50 g carbohydrate as a glucose solution. Fructose-to-glucose ratios were 1.09, 1.12, 1.03, 1.54, for clover, buckwheat, cotton, and tupelo, respectively. Blood was collected after an overnight fast and 15, 30, 45, 60, 90, and 120 minutes after intake. Ten minutes were allowed for food consumption. Areas under the glycemic response curves for each honey were expressed as percent means of each participant's average response to glucose feedings. The means (+/-standard error) of the glycemic index were 69.2+/-8.1, 73.4+/-6.4, 73.6+/-6.6, 74.1+/-8.2 for clover, buckwheat, cotton, and tupelo honeys, respectively. No statistically significant differences between the honeys were apparent, nor was a relationship between glycemic index and the fructose-to-glucose ratio detected, indicating that small differences in fructose-to-glucose ratios do not substantially impact honey glycemic index.

Glycemic index, glycemic load, and pancreatic cancer risk (Canada)

There is some evidence that plasma insulin and postload plasma glucose may be associated with risk of pancreatic cancer. Glycemic index and glycemic load are measures, which allow the carbohydrate content of individual foods to be classified according to their postprandial glycemic effects and hence their effects on circulating insulin levels. Therefore, we examined pancreatic cancer risk in association with glycemic index (GI), glycemic load (GL), and intake of dietary carbohydrate and sugar in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths, with follow-up ending between 1998 and 2000. During a mean 16.5 years of follow-up, we observed 112 incident pancreatic cancer cases. There was no association between overall glycemic index, glycemic load, total carbohydrate and total sugar intake and pancreatic cancer risk. In multivariate adjusted models, the hazard ratio (HR) for the highest versus lowest quartile levels of overall GI and GL were 1.43 (95% confidence interval [CI]=0.56-3.65, P(trend)=0.58) and 0.80 (95% CI=0.45-1.41, P(trend)=0.41), respectively. Our data suggest that overall glycemic index and glycemic load, as well as total sugar and total carbohydrate intake, are not associated with pancreatic cancer risk. However, given the limited literature regarding the role of diet in the etiology of pancreatic cancer, particularly with respect to glycemic index/load, further investigation is warranted.

Dietary carbohydrates and breast cancer risk: A prospective study of the roles of overall glycemic index and glycemic load

We examined breast cancer risk in association with overall glycemic index (GI), glycemic load (GL), and dietary carbohydrate and sugar intake in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000. During a mean follow-up of 16.6 years, we observed 1,461 incident breast cancer cases. GI, GL, total carbohydrate and total sugar intake were not associated with breast cancer risk in the total cohort. However, there was evidence of effect modification of the association between GI and breast cancer risk by menopausal status (p = 0.01), the hazard ratio for the highest versus the lowest quintile level of GI being 0.78 (95% CI = 0.52-1.16; ptrend = 0.12) in premenopausal women and 1.87 (95% CI = 1.18-2.97; ptrend = 0.01) in postmenopausal women. The associations between GI and GL were not modified by body mass index (BMI) or by vigorous physical activity among pre- or postmenopausal women. Similarly, the associations between GI/GL and risk in postmenopausal women were not modified by BMI, vigorous physical activity, or ever use of hormone replacement therapy (HRT), although the associations were slightly stronger among those who reported no vigorous physical activity (ptrend = 0.02), among those who reported ever using HRT (ptrend = 0.02) and among normal-weight women (BMI < 25 kg/m2; ptrend = 0.03). Our data suggest that consumption of diets with high GI values may be associated with increased risk of breast cancer among postmenopausal women, possibly more so among subgroups defined by participation in vigorous physical activity, ever use of HRT and those who are not overweight.

Glycemic load, carbohydrate intake, and risk of colorectal cancer in women: a prospective cohort study

Mounting evidence suggests that high circulating levels of insulin might be associated with increased colorectal cancer risk. The glycemic effects of diets high in refined starch may increase colorectal cancer risk by affecting insulin and/or insulin-like growth factor-I levels. We examined the association between dietary intake and colorectal cancer risk in a cohort of 49 124 women participating in a randomized, controlled trial of screening for breast cancer in Canada. Linkages to Canadian mortality and cancer databases yielded data on mortality and cancer incidence up to December 31, 2000. During an average 16.5 years of follow-up, we observed 616 incident cases of colorectal cancer (436 colon cancers, 180 rectal cancers). Rate ratios for colorectal cancer for the highest versus the lowest quintile level were 1.05 (95% confidence interval [CI] = 0.73 to 1.53; P(trend) =.94) for glycemic load, 1.01 (95% CI = 0.68 to 1.51; P(trend) =.66) for total carbohydrates, and 1.03 (95% CI = 0.73 to 1.44; P(trend) =.71) for total sugar. Our data do not support the hypothesis that diets high in glycemic load, carbohydrates, or sugar increase colorectal cancer risk.

Acute fructose administration improves oral glucose tolerance in adults with type 2 diabetes

OBJECTIVE

In normal adults, a small (catalytic) dose of fructose administered with glucose decreases the glycemic response to a glucose load, especially in those with the poorest glucose tolerance. We hypothesized that an acute catalytic dose of fructose would also improve glucose tolerance in individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Five adults with type 2 diabetes underwent an oral glucose tolerance test (OGTT) on two separate occasions, at least 1 week apart. Each OGTT consisted of 75 g glucose with or without the addition of 7.5 g fructose (OGTT + F or OGTT - F), in random order. Arterialized blood samples were collected from a heated dorsal hand vein twice before ingestion of the carbohydrate and every 15 min for 3 h afterward.

RESULTS

The area under the curve (AUC) of the plasma glucose response was reduced by fructose administration in all subjects; the mean AUC during the OGTT + F was 14% less than that during the OGTT - F (P < 0.05). The insulin AUC was decreased 21% with fructose administration (P = 0.2). Plasma glucagon concentrations declined similarly during OGTT - F and OGTT + F. The incremental AUC of the blood lactate response during the OGTT - F was approximately 50% of that observed during the OGTT + F (P < 0.05). Neither nonesterified fatty acid nor triglyceride concentrations differed between the two OGTTs.

CONCLUSIONS

Low-dose fructose improves the glycemic response to an oral glucose load in adults with type 2 diabetes, and this effect is not a result of stimulation of insulin secretion.

Metabolic, hormonal and gastric fluid and pH changes after different preoperative feeding regimens

PURPOSE

To evaluate the metabolic, hormonal and gastric fluid and pH changes after administration of a small volume of different preoperative feeding regimens.

METHODS

In a prospective, randomized, double-blind study 375 adult patients were allocated to one of five groups. Patients ingested 60 ml honey, glucose-fructose-sucrose-maltose mixture (GFSM), apple juice or water two hours before surgery or continued their overnight fast (controls). Blood samples were obtained from an indwelling venous catheter before the administration of feeding regimens and before induction of anesthesia for determination of glucose, triglycerides, insulin, epinephrine and norepinephrine concentrations. Before anesthesia induction, patients were asked to grade the degree of thirst and hunger. After tracheal intubation residual gastric volume (RGV) was suctioned through an orogastric tube.

RESULTS

Administration of honey, GFSM, apple juice or water resulted in increases in RGV without changes in the gastric pH. The median RGV values were 15 ml in controls and 20-25 ml in other groups. Thirst was noted after administration of fluids containing sugars. Hunger was noted in the apple juice group. Plasma concentrations of glucose increased and triglycerides decreased after ingestion of fluids containing sugars. Plasma insulin concentrations decreased in GFSM and apple juice groups. Norepinephrine concentrations increased in the control, apple juice and water groups.

CONCLUSIONS

Small volumes of fluid increased RGV (P < 0.05). Apple juice resulted in increased incidence of thirst and hunger and plasma glucose and norepinephrine concentrations. Compared with GFSM or apple juice, honey had a gentler effect on plasma glucose and insulin concentrations.

Glycemic index in the diet of European outpatients with type 1 diabetes: relations to glycated hemoglobin and serum lipids

BACKGROUND

Little is known about the variation of the glycemic index (GI) in the diet of European outpatients with type 1 diabetes and how the GI of a commonly consumed diet is associated with metabolic control.

OBJECTIVE

The present study examined the calculated dietary GI of European outpatients with type 1 diabetes for possible relations to glycated hemoglobin (Hb A(1c)) and serum lipid concentrations.

DESIGN

The relation of the GI (calculated from a 3-d dietary record) to Hb A(1c), serum cholesterol (total, LDL, and HDL), and fasting triacylglycerol was analyzed in 2810 people with type 1 diabetes from the EURODIAB Complications Study.

RESULTS

The GI was independently related to Hb A(1c) (P = 0.0001). Compared with the highest GI quartile (median GI: 89), adjusted Hb A(1c) in the lowest GI quartile (median GI: 75) was 11% lower in patients from southern European centers and 6% lower in patients from northern, western, and eastern European centers. Of the serum lipids, only the HDL cholesterol in patients from these European centers was independently related to the GI (P = 0.002). In southern European centers, the consumption of pasta, temperate-climate fruit, white bread, and potatoes largely determined the patients' dietary GI, whereas in the northern, western, and eastern European centers, consumption of bread, potatoes, and temperate-climate fruit was most relevant.

CONCLUSIONS

This study in European patients with type 1 diabetes showed that a lower dietary GI is related to lower Hb A(1c) concentrations, independently of fiber intake. The consumption of bread and pasta had the biggest effect on the overall dietary GI of European outpatients.

Effects of glucose, galactose, and lactose ingestion on the plasma glucose and insulin response in persons with non-insulin-dependent diabetes mellitus

Galactose usually is ingested as lactose, which is composed of equimolar amounts of glucose and galactose. The contribution of galactose to the increase in glucose and insulin levels following ingestion of equimolar amounts of galactose and glucose, or lactose, has not been reported in people with non-insulin-dependent diabetes mellitus (NIDDM). Therefore, we studied the effects of galactose ingestion alone, as well as with glucose either independently or in the form of lactose, in subjects with untreated NIDDM. Eight male subjects with untreated NIDDM ingested 25 g glucose, 25 g galactose with or without 25 g glucose, or 50 g lactose as a breakfast meal in random sequence. They also received 50 g glucose on two occasions as a reference. Water only was given as a control meal. Plasma galactose, glucose, glucagon, alpha-amino nitrogen (AAN), nonesterified fatty acids (NEFA), and serum insulin and C-peptide concentrations were determined over a 5-hour period. The integrated area responses were quantified over the 5-hour period using the water control as a baseline. Following ingestion of 25 g galactose, the maximal increase in plasma galactose concentration was 1 mmol/L. The mean maximal increases in plasma galactose concentration following ingestion of 25 g galactose + 25 g glucose or following 50-g lactose meals were similar and were only 12% of that following ingestion of galactose alone (P < .05). The mean galactose area response over the water control for the 25-g galactose meal was 0.95 +/- 0.31 mmol.h/L.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of glycaemic control in non-insulin-dependent diabetes mellitus

Blood glucose profiles, fasting blood glucose and glycated haemoglobin were followed prospectively for 6 weeks in 14 patients with non-insulin-dependent diabetes (NIDDM). Capillary blood glucose was sampled weekly on filter paper and analysed in the laboratory. Glycated haemoglobin was determined every other week with both cation-exchange chromatography (HbA1-IEC) and aminophenylboronic acid affinity chromatography (GHb-PBA). The mean for the blood glucose profiles was 11.2 +/- 3.5 mmol l-1 (+/- SD) and the mean for fasting blood glucose was 9.5 +/- 2.8 mmol l-1. For individual patients the differences between mean fasting blood glucose and mean blood glucose varied from -1.3 to 4.2 mmol l-1. There was a linear relationship between blood glucose and glycated haemoglobin which was steeper for GHb-PBA than for HbA1-IEC. The correlations with fasting blood glucose and mean blood glucose for HbA1-IEC were r = 0.85 and r = 0.92 and for GHb-PBA r = 0.87 and r = 0.96 respectively. Mean blood glucose was better correlated to glycated haemoglobin than fasting blood glucose (p < 0.05 for GHb-PBA).

Lack of glucose elevation after simulated tube feeding with a low-carbohydrate, high-fat enteral formula in patients with type I diabetes

PURPOSE

Commercially available enteral formulas frequently cause hyperglycemia. This often leads to difficult and complex diabetes management with glucosuria and urinary losses of calories, fluid, and electrolytes. In this study, we compared a new product, EN-8715 (8% soluble fiber, 18% Polycose, 7% fructose, 50% fat, 17% protein), with a standard feeding product, Ensure HN (53% simple carbohydrates, 30% fat, 17% protein), to determine whether the new product would lower the glucose response.

PATIENTS AND METHODS

Ten subjects (four women and six men) with type I diabetes were evaluated in paired, simulated tube feeding studies. After an overnight fast, a Biostator (artificial endocrine pancreas) was attached to each subject, and a steady-state blood glucose level of 150 mg/dL (8.4 mM) was established. The Biostator was then programmed to deliver a small basal amount of insulin (0.1 mU/kg/minute [718 pmol/kg/minute]), and the patients were given 20 mL of the randomly assigned formula every 15 minutes for 240 minutes (320 mL). Counterregulatory hormone responses to bringing the initial glucose response to the two enteral feeding formulas were measured and compared.

RESULTS

The glucose response (mg/dL/four hours +/- SEM) essentially did not rise after EN-8715 (-2 +/- 33 mg/dL/four hours [-0.11 +/- 1.83 mM/four hours]) compared with that for Ensure HN (190 +/- 32 mg/dL/four hours [10.64 +/- 1.79 mM/four hours]). Urinary glucose losses (g +/- SEM) were significantly (p = 0.01) less after the new product (1.4 +/- 0.6 g [7.8 +/- 3.3 mmol] versus 5.7 +/- 1.5 g [30.2 +/- 8.3 mmol]). There were no significant differences in counterregulatory hormone responses. Side effects were minimal and product acceptance was similar.

CONCLUSION

A low-carbohydrate, fiber-containing enteral feeding formula can limit hyperglycemia in patients with type I diabetes.

Effects of several simple sugars on serum glucose and serum fructose levels in normal and diabetic subjects

Fructose has a reaction constant 7.5 times as high as that of glucose in its nonenzymatic reaction with protein in vitro. The effects of glucose, sucrose and fructose ingestion on serum fructose and glucose levels were studied to evaluate the overall biohazard, i.e., the probability of their altering proteins while circulating in the blood. Normal and diabetic subjects were given either 75 g glucose, 75 g fructose, 75 g sucrose, or 112.5 g fructose after fasting, and their serum levels of sugars were measured at 0, 1, 2 and 3 h. In normal subjects, fructose ingestion produced significantly lower serum glucose levels and significantly higher serum fructose levels than did glucose ingestion, while sucrose produced intermediate results. The glycemic effect was found to be lowest for fructose and highest for glucose. The calculated overall biohazard was, however, highest for fructose and lowest for glucose in normal subjects. Furthermore, the serum fructosemic index was directly proportional to the amount of fructose ingested. In diabetic subjects, blood fructose clearance was significantly more delayed than in the controls when the same amount of fructose was ingested. These results suggest that an evaluation of the effects of simple in the diabetic diet requires a closer examination of the overall biological effects of the sugars.

Blood glucose and plasma insulin responses to fat-free milk and low-lactose fat-free milk in young type 1 diabetics

The blood glucose and plasma insulin responses to test milk samples were studied in eight insulin-dependent diabetics. After an overnight fast, the subjects (aged 20-45 years) were given a breakfast containing two Weetabix biscuits (20 g carbohydrate) with 500 ml of either regular (S) fat-free milk (25 g lactose) or 500 ml of a new low-lactose (D) fat-free milk (3.75 g lactose and 4.25 g fructose). The regular morning insulin dose was omitted. Mean basal plasma glucose level was slightly higher before S milk (11.4 vs. 10.1 mmol/l). The peak increment in plasma glucose was higher in S milk (9.4 vs. 6.6 mmol/l). The rise was 83% above basal (S) vs. 65% (D). Although the final mean plasma glucose concentration was not significantly higher 3 h after S milk compared with D milk (17.9 vs. 14.3 mmol/l) the incremental area under the plasma glucose curve was much greater (p less than 0.001) with S milk than with D milk (1266 +/- 295 units vs. 909 +/- 242 units). No galactose was detectable in any sample and there was no difference in plasma beta-hydroxybutyrate levels. The results suggest that the low-lactose fat-free milk (D) may be suitable for diabetic diets and weight reducing diets due to the lower contribution of energy. The results suggest that fat-free milk does not exert a fast action on blood glucose concentration and therefore fat-free milk and especially low-lactose fat-free milk may also prove to be suitable for diabetic diets.

Influence of salt on glycaemic response to carbohydrate loading

The effect of dietary salt on glycaemic responses to different test meals was investigated. Eight healthy male volunteers ate four test meals on consecutive mornings and in random order; the meals were 50 g carbohydrate taken as a 20% glucose solution or as boiled macaroni with and without supplementation with 6 g salt. In contrast with other reports, no significant differences in peak plasma glucose concentrations or areas under the plasma glucose curves could be established. These findings do not support a beneficial effect of salt restriction on glycaemic control in diabetes.

Delaying carbohydrate absorption in noninsulin-dependent diabetes mellitus: useful therapy?

Epidemiological and psychological studies have revealed major difficulties in motivating diabetic patients to observe a long-term dietary regimen. Therefore, manipulation of intestinal digestion or absorption appears to be a feasible therapeutic approach in the management of diabetes. The addition of natural or chemically processed fiber has been shown to decrease both the postprandial and fasting blood glucose in type-2 diabetics by delaying carbohydrate absorption. Recently, selective enzyme inhibitors of glycoside hydrolases in the upper intestine have been found which create a moderate degree of malabsorption of carbohydrates. The postprandial blood sugar response can be reduced by 50%. However, both these forms of treatment may not be accepted by patients because of impalatability or gastrointestinal side effects. At present only short-term studies with each group of substances are available. Whether the reduction of hyperglycemia is sufficient for the prevention of complications must be clarified in long-term trials.

Blood glucose and plasma insulin responses to fat free milk and low-lactose fat free milk in healthy human volunteers

The blood glucose and plasma insulin responses to test milk samples were studied in healthy normal volunteers. After an overnight fast the subjects were given 500 ml of either regular fat free milk (approximately 25 g lactose) or 500 ml of a new low-lactose fat free milk (3.75 g lactose and 4.25 g fructose). Blood glucose levels were not significantly altered after either milk sample, but plasma insulin responses were significantly elevated after milk consumption. The response was slightly but not significantly higher after regular fat-free milk than after the low-lactose fat free milk. The results suggest that fat free milk does not exert a fast effect on blood glucose concentration and therefore fat free milk and especially low-lactose fat free milk may prove to be suitable for diabetic diets.

Salt and the glycaemic response

The possibility that salt increases plasma glucose and insulin responses to starchy foods was investigated. Six healthy adults took four morning test meals randomly: 50 g carbohydrate as cooked lentils or white bread, with or without 4.25 g of added salt (an amount within the range of salt found in a meal). When salt was added to the lentils the incremental area under the three hour plasma glucose curve was significantly greater than that for lentils alone (43.2 mmol.min/l v 11.1 mmol.min/l (778 mg.min/100 ml v 200 mg.min/100 ml]. When salt was added to bread the peak glucose concentration was significantly higher than that for unsalted bread (6.96 mmol/l v 6.35 mmol/l (125 mg/100 ml v 114 mg/100 ml], and this was followed by relative hypoglycaemia. Plasma insulin concentrations at 45 minutes were higher after a meal of salted lentils and salted bread than after the unsalted foods (p less than 0.05). The high insulin concentration after salted bread was sustained for one hour after the meal, thus the mean area under the three hour curve was 39% greater than that for unsalted bread (p less than 0.05). Salt may increase the postprandial plasma glucose and insulin responses to lentils and bread by accelerating the digestion of starch by stimulating amylase activity or accelerating small intestinal absorption of the liberated glucose, or both. The findings of this preliminary study, if confirmed by others, would support the recommendation that diabetics, as well as the general population, should reduce their intake of salt.

The glycaemic index of foods

The glycaemic index is a measure of the extent to which the carbohydrate in a food can raise the blood glucose concentration and helps to identify foods which may be beneficial to a diabetic patient. This paper reviews the results that have been obtained so far with the glycaemic index approach, the factors that affect the glycaemic response, the problems that are associated with its measurement and its value in planning diabetic diets. Individual variation and variation among individuals in glycaemic responses are also discussed.

Plasma glucose responses to glucose, sucrose, and honey in patients with diabetes mellitus: an analysis of glycaemic and peak incremental indices

We have studied the hyperglycaemic effect of the carbohydrate of glucose, sucrose, and honey equivalent to 20 g in twelve normal volunteers, eight patients with insulin-dependent diabetes mellitus (IDDM), and six patients with non-insulin-dependent diabetes mellitus (NIDDM). Honey produced an attenuated postprandial glycaemic response in normal volunteers (vs glucose p less than 0.005; vs sucrose p less than 0.05) and IDDMs (vs glucose p less than 0.005; vs sucrose p less than 0.05). The glycaemic index (GI) showed considerable variability within each subject group. Combined with a peak incremental index (PI), the two indices appear to be more valuable in predicting the glycaemic effects of carbohydrates rather than either one alone. We suggest that honey may prove to be a valuable sugar substitute in diabetics, and that both the GI and PI should be used in the analysis of food.